This old male (named Tag) died of cancer in 2008 after more than a decade of living at the aquarium. I was there a month ago and there is now a new Steller's sea lion in the exhibit, and it shares its pool with 3 harbour seals.
That's sad. I visited Vancouver a few years ago and remember him. He was huge! I remember being told they didn't use him in the backstage sealion encounters. Not because he was likely to attack anyone, but because if he got scared of something he could flatten anyone in his path!